Just a follow up.
Rather than sitting on the beach crying about no diving, I ended up doing 3 back to back tours with G Adventures (formerly GAP). I toured from Singapore through Malaysia to Bangkok (BKK). Then from BKK through Northern Thailand and back to BKK where I picked up the last tour through Southern Thailand.
I had no idea about the diving out of Krabi or Phuket b/c that was not my focus. Eventually, I ended up in Koa Tao for the last 2 weeks. The first day I went on a snorkeling tour around the Island and was not impressed. I found a small operator called Goodtime Adventures and they catered to my needs.
I did some amazing, but easy diving with only a GroPro Hero in tow. The Gulf of Thailand does not offer that much in the way of advanced diving, but I was able to go to Sail Rock, Chumphon Marine Park, Chumphon Pinnacles, Southwest Pinnacles and some dives around the "other side" of Koa Tao. I wore my sling until time to dive and I got in the water, they dropped in my gear, I put it on and off we went. Reversed the process at the end of the dive and never had to carry a tank. There was never a rough day that made me question whether I should go or not and although the visibility can be poor at times, I was rewarded with amazing viz and great dives in a semi- controlled environment. I never once felt like I put my shoulder at risk.
Now finally at 4 months out, I am allowed to start increasing range of motion and hope to start strength training in another week. I'm excited as I feel I have a great repair and look forward to using my right shoulder as it was intended for the first time in over 40 yrs.
Thanks for all your input. Now will have to go back and check out Phi Phi, Similans and Phuket as dive locales.